From Anna Nowogrodzki at Nature:
The 423-million-year-old specimen, dubbed Qilinyu rostrata, is part of an ancient group of armoured fish called placoderms. The fossil is the oldest ever found with a modern three-part jaw, which includes two bones in the upper jaw and one in the lower jaw. Researchers reported their find on 20 October in Science.
Scientists had thought that placoderm jaws were only very distantly related to the three-part jaw found in modern bony fish and land vertebrates, including people.
“You know that old thing where you have a picture of a vase and you suddenly realize that it’s two human profiles facing each other? It was like that,” Ahlberg recalls. “You realize that what everybody else has ruled out is in fact not only not ruled out, but is in fact the crushingly obvious interpretation.” More.
So “modern jaws” turn out to be very old?
See also: Stasis: Life goes on but evolution does not happen
Follow UD News at Twitter!